A spinal fracture and dislocation reduction device

Abstract

The present application provides a kind of spinal fracture vertebral body dislocation reduction device, belong to medical instrument technical field.Device includes distractor, pre-implanted in the upper cone and lower cone two sides of fractured cone pedicle screw, distractor is provided with two groups, respectively for distracting the upper cone and lower cone left side of pedicle screw and the upper cone and lower cone right side of pedicle screw, the acting end of distractor is equipped with connecting piece, for detachably connecting the head of pedicle screw, connecting rod is provided with at least two groups, for supporting pedicle screw after the withdrawal of distractor;It also includes auxiliary connecting piece.In the above scheme, by setting auxiliary connecting piece, it is realized that connecting rod is installed in advance in the state of the continuous work of distractor.When the distractor maintains the distraction force, the doctor can pass through the through slot of auxiliary connecting piece and place into the U-shaped slot of pedicle screw, and then remove the distractor after the locking of connecting rod, ensure the long-term stability of the reduction state.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a device for reducing vertebral dislocation caused by spinal fracture. Background Technology

[0002] Spinal fractures combined with vertebral dislocation are a serious type of trauma in spinal surgery, commonly seen in high-energy injuries such as falls from heights and traffic accidents. This type of injury not only leads to loss of vertebral height and kyphosis, but more seriously, it can cause space-occupying lesions within the spinal canal, compressing the spinal cord or nerve roots, resulting in varying degrees of neurological dysfunction, and even paraplegia. Therefore, early, effective, and safe reduction and fixation are crucial for treatment.

[0003] Currently, the posterior pedicle screw-rod fixation system is the most widely used technique in clinical treatment of spinal fractures and dislocations. Its basic procedure is as follows: First, pedicle screws are inserted into the fractured vertebra and adjacent vertebral bodies above and below. Then, a spreader is used to apply longitudinal distraction force between the vertebral bodies above and below. This distraction force is transmitted through the intact posterior and anterior longitudinal ligaments, utilizing the "tent effect" of the ligaments to indirectly distract the compressed vertebral body, restore vertebral height, and partially reposition any bone fragments protruding into the spinal canal, thereby achieving indirect decompression. This technique, known as "ligament reduction," is the core of the pedicle screw system's reduction mechanism.

[0004] The existing procedure for using pedicle screws with a diffuser has a significant and unresolved technical flaw: after reduction and distraction, the diffuser must be removed before the connecting rod is installed and locked. After the diffuser is removed, unpredictable micro-movements occur between the upper and lower vertebrae, causing changes in the previously aligned screw head positions. When the connecting rod is then placed, problems such as mismatch between the rod's curvature and the screw head position, or inconsistent screw head heights, often arise. Surgeons need to use a rod-pressor to forcibly press the connecting rod into the screw head's U-groove, or perform intraoperative secondary bending of the connecting rod. This "forced rod pressing" not only increases the difficulty of the surgery but may also create additional stress on the already reduced vertebrae, potentially leading to iatrogenic fractures or screw pullout, resulting in low surgical efficiency. Summary of the Invention

[0005] This invention provides a spinal fracture vertebral dislocation reduction device to solve the technical problems that occur after the removal of existing spreaders, the relative position between the upper and lower vertebrae may undergo unpredictable micro-movements, causing changes in the position of the originally aligned screw heads. When a connecting rod is then placed, mismatches often occur between the curvature of the connecting rod and the screw head position, and inconsistent screw head heights, making it difficult to maintain the reduction state, difficult to install the connecting rod, and resulting in low surgical efficiency.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A spinal fracture vertebral body dislocation reduction device includes a pedicle screw, an auxiliary connector is embedded in the top of the pedicle screw, a connector is threaded to the top of the pedicle screw, and the connector is inserted into the auxiliary connector.

[0008] The connectors on two adjacent pedicle screws are respectively connected to the fixing part and the output part of the drive component, so that the distance between the fixing part and the output part of the drive component can be adjusted. A connecting rod is connected between the auxiliary connectors on two adjacent pedicle screws.

[0009] Optionally, each of the connecting components includes a connecting frame disposed at the working end of the expander, and a connecting shaft is rotatably connected to the surface of each connecting frame. Each connecting shaft is provided with a threaded connector and a nut at its lower part. The nut is located above the threaded connector, and the threaded connector is threadedly connected to the head of the pedicle screw.

[0010] Optionally, each of the auxiliary connectors includes a mounting block that is adapted to the groove of the pedicle screw. The height of the mounting block is less than the depth of the pedicle screw. The surface of the mounting block is provided with a through groove for inserting a connecting rod. Limiting portions are provided on both sides of the mounting block. The opposite side of the limiting portion is provided with an arc surface adapted to the outer surface of the head of the pedicle screw. When the mounting block is installed in the groove of the head of the pedicle screw, the two sets of limiting portions contact the outer wall of the head of the pedicle screw to form a lock in the horizontal direction.

[0011] Optionally, both ends of the mounting block and the connecting rod are provided with matching connecting holes, and connecting bolts are inserted into the connecting holes.

[0012] Optionally, each of the mounting blocks is fixedly connected with a rod, and each of the connecting frames is fixedly connected with a cylinder. The rod and the cylinder are inserted into each other, and the insertion direction of the rod and the cylinder is perpendicular to the opening direction of the spreader.

[0013] Optionally, the spreader further includes a driving component, each of which includes a housing. The housing contains a gear and a toothed plate. The gear is rotatably mounted inside the housing, and the toothed plate meshes with the gear. Side openings are provided on both sides of the outer surface of the housing. Both ends of the toothed plate extend to the outside of the housing through the side openings, and the toothed plate is slidably connected to the side openings.

[0014] Optionally, flexible protective sleeves are fixedly connected between both ends of the toothed plate and the housing, and the protective sleeves are used to protect the teeth of the toothed plate located on the outside of the housing.

[0015] Optionally, each set of the expander has two sets of working ends, one set located at one end of the toothed plate and the other set located at the lower part of the housing, with the two sets of working ends arranged opposite to each other.

[0016] Optionally, a rotating component is provided between the two sets of spreaders to drive the two sets of gears to rotate. The rotating component includes a drive shaft that passes through the two sets of housings and gears. The drive shaft, housing, and gears are movably coupled. A coaxial annular plate is fixedly connected to one side of each gear. At least three sets of annularly distributed electric cylinders are provided on the surface of the annular plate. A pressure plate is fixedly connected to the side of each electric cylinder located inside the annular plate. The pressure plate is designed with an arc-shaped structure adapted to the drive shaft. A support plate is fixedly connected to the surface of one set of housings. The support plate is designed with an L-shape. One end of the drive shaft is rotatably connected to the short side of the support plate. A crank is fixedly connected to the end of the drive shaft near the support plate.

[0017] Optionally, a groove adapted to the long side of the support plate is provided at the bottom of the housing away from the crank handle. The long side of the support plate slides through the groove. A positioning bolt is inserted into the housing and abuts against the surface of the support plate.

[0018] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0019] In the above solution, by setting up an auxiliary connector, the connecting rod can be installed in advance while the spreader is continuously working. While the spreader maintains the spreading force, the doctor can pass the connecting rod through the through groove of the auxiliary connector and place it into the U-shaped groove of the pedicle screw. After the connecting rod is locked, the spreader is removed to ensure long-term stability of the reduction state. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the spinal fracture vertebral dislocation reduction device of the present invention when the spreader is connected to the pedicle screw;

[0021] Figure 2 This is an exploded view of the pedicle screw, auxiliary connector, and connector in the spinal fracture vertebral dislocation reduction device of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the spinal fracture vertebral dislocation reduction device of the present invention when the connecting rod is installed in the open state of the spreader;

[0023] Figure 4 This is a schematic diagram of the structure of the spinal fracture vertebral dislocation reduction device of the present invention after the connecting rod is installed and the spreader is removed.

[0024] Figure 5 This is a cross-sectional view of the drive component in the spinal fracture vertebral dislocation reduction device of the present invention;

[0025] Figure 6 This is a partial structural diagram of the spinal fracture vertebral dislocation reduction device of the present invention;

[0026] Figure 7This is a schematic diagram of the gears and toothed plates in the spinal fracture vertebral dislocation reduction device of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of the spinal fracture vertebral dislocation reduction device of the present invention when the spreader is connected to the pedicle screw;

[0028] Figure 9 This is a schematic diagram of the locator in the spinal fracture vertebral dislocation reduction device of the present invention.

[0029] [Figure Labels]

[0030] 1. Pedicle screws;

[0031] 2. Auxiliary connector; 21. Mounting block; 22. Through groove; 23. Insert rod; 24. Limiting part; 25. Connecting hole;

[0032] 3. Connecting parts; 31. Connecting bracket; 32. Threaded connector; 33. Nut; 34. Connecting shaft; 35. Insert sleeve;

[0033] 4. Drive component; 41. Housing; 42. Gear; 43. Tooth plate; 44. Side opening; 45. Protective sleeve; 46. Pawl; 47. Compression spring; 48. Ratchet;

[0034] 5. Rotating component; 51. Crank handle; 52. Drive shaft; 53. Annular plate; 54. Support plate; 55. Electric cylinder; 56. Pressure plate; 57. Slide groove; 58. Positioning bolt;

[0035] 6. Connecting rod; 7. Connecting bolt. Detailed Implementation

[0036] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0037] like Figures 1 to 4 As shown, an embodiment of the present invention provides a spinal fracture vertebral dislocation reduction device, including a spreader, pedicle screws 1 pre-inserted on both sides of the upper and lower vertebrae of the fractured vertebra, and connecting rods 6. Two sets of spreaders are provided, respectively used to spread the pedicle screws 1 on the left side of the upper and lower vertebrae and the right side of the upper and lower vertebrae. Each working end of the spreader is provided with a connector 3 for detachably connecting to the head of the pedicle screw 1. At least two sets of connecting rods 6 are provided for supporting the pedicle screws 1 after the spreader is removed. An auxiliary connector 2 is also included, which can be used to install the connecting rods 6 when the spreader acts on the pedicle screws 1.

[0038] In this embodiment, before the surgical procedure, the surgeon first inserts pedicle screws 1 into the fractured vertebral body and its adjacent upper and lower vertebral bodies on both sides. The heads of these pedicle screws 1 have a standard U-shaped groove structure for subsequently accommodating auxiliary connectors 2 and connecting rods 6. After screw placement, the surgeon places the auxiliary connectors 2 into the grooves of the pedicle screws 1 to facilitate the connection between the connecting rods 6 and the auxiliary connectors 2 while the spreaders are still in place. Subsequently, the surgeon installs two sets of spreaders on the left and right sides of the spine, respectively. Each set of spreaders establishes a rigid connection with the heads of the upper and lower vertebral pedicle screws 1 on the same side through the connector 3 at its working end. At this point, the two sets of spreaders each span between the upper and lower vertebral bodies. It should be noted that the insertion of the auxiliary connectors 2 does not affect the connection between the connectors 3 and the pedicle screws 1. The surgeon drives two sets of retractors to generate longitudinal dispersing force. Since the working ends of the retractors are fixed to the pedicle screws 1 of the upper and lower vertebral bodies respectively, the elongation movement of the retractors forces the upper and lower vertebral bodies away from each other. This dispersing force is transmitted to the vertebral body through the pedicle screws 1, and then to the fractured vertebral body through the intact anterior and posterior longitudinal ligaments. The "tent effect" of the ligaments causes the compressed fractured vertebral body to be axially pulled apart, restoring its height, while the bone fragments protruding into the spinal canal are indirectly pulled back, achieving reduction of the fractured vertebral body. In this situation, the connecting rod 6 is installed through the auxiliary connector 2, allowing the connecting rod 6 to be temporarily or permanently positioned in the U-shaped groove of the pedicle screw 1 without interfering with the normal operation of the retractors. That is to say, the surgeon can complete the placement and initial fixation of the connecting rod 6 while the retractors are still in place and the dispersing force is maintained. Once the connecting rod 6 is locked, the dispersing force of the retractors is actually "stored" in the internal fixation system through the connecting rod 6. At this point, even if the diffuser is removed, the vertebral height and kyphosis correction previously achieved through the diffuser are fully preserved because the connecting rod 6 has rigidly connected the pedicle screws 1 of the upper and lower vertebrae together, and there will be no loss of reduction. Finally, the doctor removes the diffuser and, if necessary, locks the connecting rod 6 to complete the internal fixation.

[0039] like Figure 2 As shown, each of the connecting parts 3 includes a connecting frame 31 set at the working end of the spreader. A connecting shaft 34 is rotatably connected to the surface of the connecting frame 31. A threaded connector 32 and a nut 33 are provided at the lower part of the connecting shaft 34. The nut 33 is located above the threaded connector 32. The threaded connector 32 is threadedly connected to the head of the pedicle screw 1.

[0040] The core function of connector 3 is to achieve a quick, rigid, and detachable connection between the working end of the retractor and the head of the pedicle screw 1. Traditional retractors typically use simple claws or calipers to hold the head of the pedicle screw 1, which is prone to slippage during the retraction process. Connector 3 of this invention uses a threaded connection, greatly improving the reliability of the connection and the efficiency of force transmission. Specifically, the doctor first aligns the threaded connector 32 with the pre-set internal threaded hole on the head of the pedicle screw 1, and then rotates the connecting shaft 34 to screw the threaded connector 32 into the head of the pedicle screw 1. As the thread is screwed in, the threaded connector 32 and the head of the pedicle screw 1 form a rigid, integrated connection. The nut 33 is located above the threaded connector 32, and its function is to further lock the nut 33 after the threaded connector 32 is tightened, preventing the connecting shaft 34 from accidentally loosening due to vibration or reaction force during the retraction process. When it is necessary to remove the retractor, the doctor only needs to rotate the connecting shaft 34 in the opposite direction to separate the threaded connector 32 from the head of the pedicle screw 1. The entire process is simple to operate, the connection is reliable, and it will not damage the head of the pedicle screw 1, thus ensuring the installation accuracy of the subsequent connecting rod 6.

[0041] like Figure 2 As shown, each auxiliary connector 2 includes a mounting block 21, which is adapted to the groove of the pedicle screw 1. The height of the mounting block 21 is less than the depth of the pedicle screw 1. The surface of the mounting block 21 is provided with a through groove 22 for the insertion of the connecting rod 6. Limiting parts 24 are provided on both sides of the mounting block 21. The opposite side of the limiting part 24 is set as an arc surface adapted to the outer surface of the head of the pedicle screw 1. When the mounting block 21 is installed in the groove of the head of the pedicle screw 1, the two sets of limiting parts 24 contact the outer wall of the head of the pedicle screw 1 to form a lock in the horizontal direction.

[0042] Before connecting the connector 3 to the head of the pedicle screw 1, the doctor places the mounting block 21 of the auxiliary connector 2 into the U-shaped groove of the head of the pedicle screw 1. Since the size of the mounting block 21 is adapted to the groove and its height is less than the depth of the groove, the mounting block 21 can be completely sunk into the groove without affecting the connection between the threaded connector 32 and the head of the pedicle screw 1. The limiting parts 24 on both sides of the mounting block 21 have arc surfaces that fit against the outer surface of the head of the pedicle screw 1. When the mounting block 21 is placed into the groove, the limiting parts 24 hug the outer wall of the head of the pedicle screw 1 from both sides, thereby locking the mounting block 21 in the groove in the horizontal direction and preventing it from shaking or falling out.

[0043] like Figures 2 to 4 Both ends of the mounting block 21 and the connecting rod 6 are provided with matching connecting holes 25, and the connecting holes 25 are internally threaded with bolts 7.

[0044] In this embodiment, after the spreader is fully extended, the connecting rod 6 is passed through the through slot 22 of the mounting block 21, and aligned with the connecting hole 25 on the mounting block 21. The doctor then passes the connecting bolt 7 through the connecting hole 25 to lock the connecting rod 6 and the mounting block 21. After locking, the threaded connector 32 is loosened, the spreader is removed, and the jacking screw is screwed into the head of the pedicle screw 1, so that the connecting rod 6 and the mounting block 21 are rigidly locked together axially. The mounting block 21 itself is also locked horizontally to the outer wall of the head of the pedicle screw 1 through the limiting part 24. Therefore, the axial position of the connecting rod 6 relative to the pedicle screw 1 is completely fixed, and no slippage can occur, thus completing the installation process of the connecting rod 6. It should be noted that in the spinal fracture vertebral dislocation reduction device, the length of the connecting rod 6 is not a fixed value, but needs to be individually selected or cut on-site according to the patient's specific surgical condition before the operation. In this application, the support length of the connecting rod 6 is actually the distance between the two connecting holes 25 on its two sides. The determination of the length of the connecting rod 6 and the cutting operation are routine operations in the existing medical field, and will not be described in detail here.

[0045] like Figure 2 As shown, each surface of the mounting block 21 is fixedly connected with a plug rod 23, and each surface of the connecting frame 31 is fixedly connected with a plug cylinder 35. The plug rod 23 and the plug cylinder 35 are inserted into each other, and the insertion direction of the plug rod 23 and the plug cylinder 35 is perpendicular to the opening direction of the spreader.

[0046] In this embodiment, the spreader is axially connected to the head of the pedicle screw 1 through the threaded connector 32, bearing the main spreading tension. At the same time, the insert rod 23 is inserted into the insert sleeve 35, forming a rigid support point perpendicular to the spreading direction. When the spreader is subjected to lateral force or bending moment, the insert rod 23-insert sleeve 35 serves as a second force-bearing point, converting the bending moment into its own supporting reaction force, thereby significantly reducing the bending stress borne by the threaded connector 32. After spreading is completed, when the spreader is removed, the insert rod 23 can be smoothly pulled out from the insert sleeve 35 without affecting subsequent operations.

[0047] like Figure 5 and Figure 7 The driving component 4 is the core power conversion mechanism of the spreader, and its function is to convert the input torque into a linear spreading force. Each driving component 4 includes a housing 41, inside which are provided gears 42 and toothed plates 43. The gears 42 are rotatably mounted inside the housing 41, and the toothed plates 43 mesh with the gears 42. Side openings 44 are provided on both sides of the outer surface of the housing 41. Both ends of the toothed plates 43 extend to the outside of the housing 41 through the side openings 44, and the toothed plates 43 are slidably connected to the side openings 44, providing a sliding track for the toothed plates 43. Each set of spreaders has two sets of operating ends: one set located at one end of the toothed plate 43, and the other set located at the lower part of the housing 41, with the two sets of operating ends arranged opposite each other.

[0048] In this embodiment, when gear 42 rotates forward, toothed plate 43 moves to one side, causing one of the working ends to move away from housing 41, thereby opening up the pedicle screws 1 on both sides. Conversely, when gear 42 rotates in the opposite direction, toothed plate 43 moves to the other side, and the two working ends move closer to each other, achieving compression.

[0049] like Figure 7 As shown, in addition to ensuring the precision of the gear 42 and the toothed plate 43, flexible protective sleeves 45 are fixedly connected to both ends of the toothed plate 43 and the housing 41. The protective sleeves 45 are used to protect the teeth of the toothed plate 43 located outside the housing 41. The protective sleeves 45 are made of flexible materials, such as medical silicone. When the toothed plate 43 moves during the opening or retraction process, the protective sleeves 45 extend, retract, or fold accordingly, always completely enclosing the part of the toothed plate 43 located outside the housing 41. Due to the sealing of the protective sleeves 45, blood, tissue fluid, and debris cannot come into contact with the teeth of the toothed plate 43, thus ensuring the cleanliness of the area between the meshing gear 42 and the toothed plate 43.

[0050] like Figures 5 to 8 As shown, a rotating component 5 is provided between the two sets of spreaders to drive the two sets of gears 42 to rotate. The rotating component 5 includes a drive shaft 52 that passes through the two sets of housings 41 and gears 42. The drive shaft 52, housings 41 and gears 42 are movably coupled. A coaxial annular plate 53 is fixedly connected to one side of each gear 42. At least three sets of annularly distributed electric cylinders 55 are provided on the surface of the annular plate 53. A pressure plate 56 is fixedly connected to the side of each electric cylinder 55 located inside the annular plate 53. The pressure plate 56 is designed with an arc-shaped structure adapted to the drive shaft 52. A support plate 54 is fixedly connected to the surface of one set of housings 41. The support plate 54 is designed as an L-shape. One end of the drive shaft 52 is rotatably connected to the short side of the support plate 54. A crank handle 51 is fixedly connected to the end of the drive shaft 52 near the support plate 54. A groove 57 adapted to the long side of the support plate 54 is opened at the bottom of the housing 41 away from the crank handle 51. The long side of the support plate 54 slides through the groove 57. A positioning bolt 58 is inserted into the housing 41, and the positioning bolt 58 abuts against the surface of the support plate 54.

[0051] In the spinal fracture vertebral dislocation reduction device, two sets of spreaders correspond to the left and right sides of the patient's spine, respectively. Due to differences in vertebral body width, pedicle screw 1 placement position, and intraoperative spinal curvature changes among different patients, the lateral distance between the two sets of spreaders needs to be adjustable to ensure that the connector 3 of each spreader can be accurately aligned with the head of the pedicle screw 1 on the same side. The doctor drives the electric cylinder 55 to retract, causing the pressure plate 56 to no longer press against the drive shaft 52. At this time, the frictional coupling between the drive shaft 52 and the gears 42 on the left and right sides is completely released, and the drive shaft 52 can slide freely axially within the central holes of the two sets of gears 42. Subsequently, the doctor loosens the positioning bolt 58, releasing its locking to the long side of the support plate 54, and moves the set of spreaders away from the crank handle 51. Based on the actual distance between the left and right pedicle screws 1 measured during the operation, the doctor slides the movable side spreader to the appropriate position so that its connector 3 can accurately align with the head of the pedicle screw 1 on the corresponding side. Once the lateral spacing is adjusted, the doctor first tightens the positioning bolt 58, ensuring its end firmly abuts against the long side surface of the support plate 54. This friction locks the movable side housing 41 onto the support plate 54. After locking, the lateral distance between the two sets of spreaders remains constant, capable of withstanding the lateral force generated during subsequent spreading without shifting. Finally, the doctor again extends the electric cylinder 55, causing the pressure plate 56 to re-press the drive shaft 52, restoring the frictional coupling between the drive shaft 52 and the gear 42. Turning the crank handle 51 then selectively transmits power to the gear 42, performing a synchronous spreading operation.

[0052] To enable independent and reliable operation of the electric cylinder 55, a small power supply component, such as a miniature rechargeable lithium battery or button cell battery pack, is installed inside or on the surface of the annular plate 53 on each side. This power supply component is electrically connected to the electric cylinder 55 on the same side, providing it with operating power. Due to the short stroke and low power consumption of the electric cylinder 55, the small power supply component is sufficient to meet the needs of multiple clutch operations throughout the surgery. Furthermore, to facilitate one-handed operation by the surgeon, the control button for the electric cylinder 55 is located on the crank handle 51. The surgeon can operate it directly with their thumb or forefinger while holding the handle 51, without the need for an additional foot switch or assistant. The extension and retraction drive and control circuit of the electric cylinder 55 are existing technologies and will not be described in detail here.

[0053] In practical applications, a corresponding positioner can also be set up to limit the gear 42 or toothed plate 43 after it is fully extended. This positioner can be a spring-loaded pawl type 46 positioner, such as... Figure 9As shown, a positioner that engages with the teeth of the toothed plate 43 is provided inside or outside the housing 41 of the drive unit 4. This positioner includes a swingable pawl 46, a compression spring 47, and a ratchet 48. The ratchet 48 is mounted on the surface of the toothed plate 43, and the end of the pawl 46 is machined into sharp teeth that match the tooth profile of the ratchet 48. The spring always presses the pawl 46 against the tooth surface of the ratchet 48. The rotation of the pawl 46 is mounted on the housing 41, and the release end extends outside the housing 41 for easy operation by the doctor. When the retractor performs a retraction operation, the toothed plate 43 moves in the retraction direction under the drive of the gear 42. During this process, the back of the teeth of the ratchet 48 pushes the pawl 46 against the spring force, lifting it up. The pawl 46 slides across the tooth surface without obstructing the retraction movement. Once the retraction reaches the target position, the doctor stops driving the gear 42, at which point the spring force presses the pawl 46 into the tooth groove of the ratchet 48. Because the toothed design of the pawl 46 is one-way locking, even if the drive torque is removed or an impact load is accidentally applied, the ratchet 48 and the toothed plate 43 cannot retract on their own, thus firmly locking the opening amount.

[0054] When the retraction spreader needs to be retracted, the doctor only needs to move the release lever to disengage the pawl 46 from the tooth groove of the toothed plate 43 to release the limit, and then reverse drive the gear 42 to retract the toothed plate 43.

[0055] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for reducing vertebral dislocation in spinal fractures, characterized in that: The device includes a pedicle screw, wherein an auxiliary connector is embedded in the top of the pedicle screw, and a connector is threadedly connected to the top of the pedicle screw, and the connector is inserted into the auxiliary connector. The connectors on two adjacent pedicle screws are respectively connected to the fixing part and the output part of the drive component, so that the distance between the fixing part and the output part of the drive component can be adjusted. A connecting rod is connected between the auxiliary connectors on two adjacent pedicle screws.

2. The spinal fracture vertebral dislocation reduction device according to claim 1, characterized in that, Each connector includes a connecting frame located at the working end of the expander. A connecting shaft is rotatably connected to the surface of each connecting frame. A threaded connector and a nut are provided at the lower part of each connecting shaft. The nut is located above the threaded connector, and the threaded connector is threadedly connected to the head of the pedicle screw.

3. The spinal fracture vertebral dislocation reduction device according to claim 2, characterized in that, Each auxiliary connector includes a mounting block that is adapted to the groove of the pedicle screw. The height of the mounting block is less than the depth of the pedicle screw. The surface of the mounting block is provided with a through groove for inserting a connecting rod. Limiting parts are provided on both sides of the mounting block. The opposite side of the limiting part is provided with an arc surface adapted to the outer surface of the head of the pedicle screw. When the mounting block is installed in the groove of the head of the pedicle screw, the two sets of limiting parts contact the outer wall of the head of the pedicle screw to form a lock in the horizontal direction.

4. The spinal fracture vertebral dislocation reduction device according to claim 3, characterized in that, Both ends of the mounting block and the connecting rod are provided with matching connecting holes, and connecting bolts are inserted into the connecting holes.

5. The spinal fracture vertebral body dislocation reduction device according to claim 4, characterized in that, Each mounting block surface is fixedly connected with a plug rod, and each connecting frame surface is fixedly connected with a plug cylinder. The plug rod and the plug cylinder are inserted into each other, and the insertion direction of the plug rod and the plug cylinder is perpendicular to the opening direction of the spreader.

6. The spinal fracture vertebral dislocation reduction device according to claim 1, characterized in that, Each drive component includes a housing, and a gear and a toothed plate are provided inside the housing. The gear is rotatably installed inside the housing, and the toothed plate meshes with the gear. Side openings are provided on both sides of the outer surface of the housing, and the two ends of the toothed plate extend to the outside of the housing through the side openings, and the toothed plate is slidably connected to the side openings.

7. The spinal fracture vertebral dislocation reduction device according to claim 6, characterized in that, Flexible protective sleeves are fixedly connected to both ends of the toothed plate and the shell. The protective sleeves are used to protect the teeth of the toothed plate located on the outside of the shell.

8. The spinal fracture vertebral dislocation reduction device according to claim 7, characterized in that, It also includes a spreader, which is provided in two sets. Each set of the spreader has two sets of working ends, one set located at one end of the toothed plate and the other set located at the lower part of the housing, with the two sets of working ends arranged opposite to each other.

9. The spinal fracture vertebral dislocation reduction device according to claim 8, characterized in that, A rotating component is provided between the two sets of spreaders to drive the two sets of gears to rotate. The rotating component includes a drive shaft that passes through the two sets of housings and gears. The drive shaft, housing, and gears are movably coupled. A coaxial annular plate is fixedly connected to one side of each gear. At least three sets of annularly distributed electric cylinders are provided on the surface of the annular plate. A pressure plate is fixedly connected to the side of each electric cylinder located inside the annular plate. The pressure plate is designed with an arc-shaped structure adapted to the drive shaft. A support plate is fixedly connected to the surface of one set of housings. The support plate is designed with an L-shape. One end of the drive shaft is rotatably connected to the short side of the support plate. A crank is fixedly connected to the end of the drive shaft near the support plate.

10. The spinal fracture vertebral dislocation reduction device according to claim 9, characterized in that, A groove is provided at the bottom of the housing away from the crank, which is adapted to the long side of the support plate. The long side of the support plate slides through the groove. A positioning bolt is inserted into the housing and abuts against the surface of the support plate.

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